Use of il1rap as a target in the preparation of a drug for preventing and / or treating liver metastasis of breast cancer

Abstract

The application relates to the field of biological medicine, and particularly relates to application of IL1RAP as a target point in preparation of a drug for preventing and / or treating liver metastasis of breast cancer. The application discloses, for the first time, a key promoting role of IL1RAP in liver metastasis of breast cancer, and fills a blank in the technical field. The application provides a clear molecular node for targeted intervention. Knocking down of IL1RAP can significantly inhibit formation of liver metastasis foci of breast cancer in mice, and a significant synergistic anti-tumor effect is generated when the IL1RAP is combined with PD-1 monoclonal antibody, and MGP + TMEM176A + infiltration of macrophages, and effectively solves a clinical problem that patients with liver metastasis have poor response to immunotherapy. The target point and the combined treatment strategy provided by the application have high scientific value, clinical development prospect and market prospect.

Description

Technical Field

[0001] This invention relates to the field of biomedicine, specifically to the application of interleukin-1 receptor helper protein (IL1RAP) as a target in the preparation of drugs for the prevention and / or treatment of liver metastases in breast cancer. Background Technology

[0002] Breast cancer is the most common malignant tumor among women, posing a serious threat to women's health worldwide. Although advances in early diagnosis and systemic treatment have significantly improved survival rates for patients with early-stage breast cancer, approximately 20%–30% of breast cancer patients develop distant metastases after diagnosis and treatment of the primary tumor, and about 90% of cancer-related deaths are attributed to metastatic events. The incidence of advanced breast cancer is increasing at a rate of 4%–6% annually, and metastasis remains the leading cause of breast cancer-related deaths.

[0003] The liver is a common site of distant metastasis in breast cancer. Clinical data shows that the incidence of liver metastasis in breast cancer is approximately 40%-50%, and this proportion is as high as 55%-75% in autopsy reports of advanced breast cancer. About 25% of metastatic breast cancer patients have the liver as their first or primary site of metastasis. Once liver metastasis occurs, it usually indicates that the disease has entered an advanced stage, and the patient's prognosis is extremely poor. The median overall survival after treatment is only 2-3 years, and the survival rate for untreated patients is less than 1 year.

[0004] Breast cancer is a heterogeneous disease, further classified into lumens, HER2-positive, and triple-negative breast cancer based on the expression status of hormone receptors (HR, including estrogen receptor ER and progesterone receptor PR) and human epidermal growth factor receptor 2 (HER2). Different molecular subtypes of breast cancer exhibit distinct organ metastasis tendencies. Luminals are more prone to bone metastasis, HER2-positive breast cancer is more likely to metastasize to the liver and lungs, while triple-negative breast cancer frequently metastasizes to the brain, lungs, and liver. A retrospective analysis of 542 breast cancer patients with liver metastases at Peking University Cancer Hospital showed that, based on receptor status classification of liver metastases, HR+ / HER2- accounted for 59.2%, HER2+ for 24.2%, and triple-negative for 16.6%. The median overall survival for the three groups was 58.0, 70.0, and 26.0 months, respectively, with triple-negative breast cancer patients with liver metastases having the worst prognosis. Notably, there is significant heterogeneity in receptor status between primary breast cancer and liver metastases, with an overall inconsistency rate of 23.6%. The inconsistencies in ER, PR, and HER2 expression were 21.0%, 38.6%, and 10.8%, respectively. This suggests that relying solely on the molecular subtyping of the primary tumor is insufficient to guide the precise treatment of patients with liver metastases. Biopsy of liver metastases to clarify their receptor status has important clinical significance.

[0005] Current treatment strategies for breast cancer liver metastases mainly include surgical resection, local ablation, systemic chemotherapy, endocrine therapy, targeted therapy, and immunotherapy. However, breast cancer liver metastases have traditionally been considered a systemic disease, and treatment plans have primarily been guided by the characteristics of the primary breast cancer. Surgical resection and local ablation are limited to a very small number of strictly selected patients with small lesions (usually <5cm), solitary or easily resectable lesions, and stable disease after systemic therapy; the proportion of patients suitable for surgery is less than 10%. Preoperative imaging assessments often underestimate the actual tumor burden, resulting in approximately 20% of cases being found to be unresectable after laparotomy. For most patients with liver metastases, systemic chemotherapy remains the primary treatment, but due to the unique "vascular co-selection" growth pattern of liver metastases—utilizing the existing vascular system of the surrounding liver parenchyma to maintain blood supply rather than relying on angiogenesis—they exhibit a low perfusion state, limiting the effective delivery of chemotherapy and immunotherapy drugs, and current treatment outcomes remain unsatisfactory. In recent years, the emergence of novel targeted drugs such as CDK4 / 6 inhibitors, PI3K / mTOR pathway inhibitors, and immune checkpoint inhibitors has brought breakthroughs in the treatment of breast cancer. However, patients with liver metastases still benefit significantly less from these treatments than patients without liver metastases, and there is an urgent need to develop new treatment strategies that target the specific organ microenvironment of liver metastases.

[0006] The liver, as a target organ for metastasis, possesses unique anatomical structures and immunological characteristics. The hepatic sinusoids are a highly permeable capillary network composed of sinusoidal endothelial cells, hepatic stellate cells, Kupffer cells, and hepatocytes. The endothelial cells have permeable sieve-like structures and lack a complete basement membrane, allowing circulating tumor cells to relatively easily enter the liver parenchyma from the bloodstream. More importantly, the liver is an organ with dual functions of immune defense and immune tolerance. Under physiological conditions, the liver maintains immune tolerance to intestinal food antigens and symbiotic microbial products through a multicellular network of Kupffer cells, sinusoidal endothelial cells, and hepatic stellate cells. However, during tumor metastasis, this immune tolerance microenvironment can be "hijacked" by tumor cells, forming "immune exemption" regions that favor metastasis and colonization.

[0007] Macrophages are the most abundant immune cell population in the liver microenvironment, mainly including Kupffer cells derived from embryonic origin and monocyte-derived macrophages derived from bone marrow. Kupffer cells reside in the hepatic sinusoidal lumen, serving as the body's first line of defense against circulating tumor cells, capturing and clearing tumor cells that enter the liver. Studies show that in liver metastases of breast cancer, compared to other common metastatic sites such as the brain and lungs, the liver metastases exhibit a more immunosuppressive microenvironment, characterized by an abundance of activated regulatory T cells and monocyte-derived macrophages, while the infiltration and activation levels of CD8+ cytotoxic T cells are relatively low. Breast tumor cells can remotely regulate the liver microenvironment by secreting various cytokines and exosomes, inducing Kupffer cell phenotypic transformation and simultaneously recruiting large numbers of monocyte-derived macrophages, polarizing them into the M2 tumor-promoting phenotype. M2 tumor-associated macrophages exert their immunosuppressive effect through multiple mechanisms, including secreting inhibitory cytokines such as IL-10 and TGF-β, expressing immune checkpoint molecules such as PD-L1 and VISTA, competing with T cells for key amino acids, and inducing regulatory T cell differentiation. These mechanisms synergistically suppress CD8+ T cell function, creating an immunosuppressive microenvironment. Therefore, tumor-associated macrophages are considered key shapers of the immunosuppressive microenvironment in breast cancer liver metastases and potential therapeutic targets.

[0008] Protein arginine methyltransferases and other molecules play important roles in regulating macrophage function, but research on the regulation of macrophage function by members of the IL-1 receptor family, especially their co-receptors, in breast cancer liver metastases is still insufficient. Interleukin-1 receptor accessory protein (IL1RAP) is a key co-receptor molecule in the IL-1 receptor family. In the classical IL-1 signaling pathway, IL-1α or IL-1β first binds to IL-1R1 to form a complex, then recruits IL1RAP to form a heterotrimeric complex, which in turn recruits myeloid differentiation factor 88 and interleukin-1 receptor activating kinase, activating downstream NF-κB and MAPK signaling pathways, initiating inflammatory responses and immune regulation. The general pattern of binding between IL-1 family cytokines (IL-1α / β, IL-33, IL-36α / β / γ) and their major receptors and IL1RAP is as follows: cytokines bind to their major receptors, inducing the recruitment of IL1RAP. A dimer forms between the receptor's intracellular domain and the intracellular TIR domain of IL1RAP, which is essential for the recruitment and binding of downstream signaling molecules such as MyD88. IL1RAP participates in three IL-1 family signaling pathways: IL-1R, IL-33R, and IL-36R, all of which exhibit pro-tumorigenic activity.

[0009] In recent years, IL1RAP has gradually gained attention as a target for cancer therapy. Studies have found that IL1RAP is upregulated in several cancers, including hematologic malignancies (such as acute myeloid leukemia and chronic myeloid leukemia) and solid tumors (pancreatic cancer, colorectal cancer, and cervical cancer). In pancreatic cancer, IL1RAP is expressed in tumor samples from most patients, and its overexpression is associated with poorer overall survival. Knockdown of IL1RAP significantly reduces cell viability, invasiveness, and clonogenic ability of pancreatic cancer cell lines. In acute myeloid leukemia, IL1RAP promotes the survival and self-renewal of leukemia stem cells by activating the IL-1 signaling pathway and is considered a potential biomarker for leukemia stem cells. In breast cancer, no studies have explored the role of IL1RAP in the specific organ microenvironment of liver metastasis, and it is unclear whether the IL1RAP of tumor cells themselves participates in regulating the process of liver metastasis and immune microenvironment remodeling.

[0010] In summary, existing treatments have limited clinical efficacy for patients with breast cancer liver metastases, necessitating the discovery of new therapeutic targets and intervention strategies. While studies have revealed the functions of the IL-1 receptor family in general mechanisms such as tumor cell proliferation and immune escape, systematic and in-depth research on its regulatory role in organ-specific metastasis remains lacking. In particular, the role of IL1RAP in breast cancer liver metastases, its regulatory mechanism on the hepatic immune microenvironment, and the therapeutic value of targeting IL1RAP are currently unreported. Therefore, elucidating the function and molecular mechanisms of IL1RAP in breast cancer liver metastases is of significant theoretical and clinical value for developing new therapeutic strategies. Summary of the Invention

[0011] The purpose of this invention is to provide a novel target for the prevention and / or treatment of liver metastases in breast cancer—IL1RAP, and its application in the preparation of related drugs.

[0012] To achieve the above objectives, the present invention adopts the following technical solution:

[0013] 1. IL1RAP is highly expressed in liver metastases of breast cancer and is associated with poor prognosis: Kaplan-Meier Plotter database analysis showed that high expression of IL1RAP was significantly associated with worse overall survival in the overall breast cancer cohort and in each molecular subtype.

[0014] 2. Knockdown of IL1RAP significantly inhibits liver metastasis of breast cancer: In a mouse model of liver metastasis by spleen injection, knockdown of IL1RAP significantly reduced the number of metastatic nodules on the liver surface and reduced liver weight, while having no effect on the growth of in situ tumors, suggesting that IL1RAP specifically regulates the process of liver metastasis.

[0015] 3. IL1RAP regulates macrophage recruitment and polarization via the NF-κB / CCL4 axis: Mechanistic studies have shown that IL1RAP in tumor cells upregulates CCL4 expression by activating the NF-κB signaling pathway. After secretion, CCL4 acts on the CCR5 receptor on the macrophage surface, promoting the recruitment of tumor-associated macrophages and M2 polarization, as well as the expression of MGP and TMEM176A molecules, creating an immunosuppressive microenvironment and thus promoting liver metastasis. This effect can be blocked using NF-κB inhibitors or CCR5 antagonists.

[0016] 4. Targeting downstream IL1RAP signals enhances the efficacy of immunotherapy: In a mouse model of liver metastasis, IL1RAP knockdown combined with PD-1 monoclonal antibody therapy significantly enhances the anti-liver metastasis effect, which is superior to single therapy.

[0017] Based on the above technical solution, the first aspect of the present invention provides the use of IL1RAP protein or its coding sequence as a drug target in the preparation of drugs for the prevention and / or treatment of liver metastases of breast cancer.

[0018] Furthermore, the drug for preventing and / or treating liver metastases of breast cancer uses IL1RAP as an intervention target, achieving its effect by inhibiting the expression or function of IL1RAP.

[0019] A second aspect of the invention provides the use of an agent that inhibits IL1RAP expression and / or function in the preparation of a medicament for the prevention and / or treatment of liver metastases from breast cancer.

[0020] Furthermore, the reagents for inhibiting IL1RAP expression and / or function include, but are not limited to:

[0021] Antibodies or antigen-binding fragments that specifically bind to IL1RAP;

[0022] Small interfering RNA (siRNA), short hairpin RNA (shRNA), antisense oligonucleotides that specifically interfere with IL1RAP gene expression, or recombinant vectors or recombinant viruses containing the above interfering molecules;

[0023] A CRISPR-Cas9 gene editing system targeting IL1RAP;

[0024] IL1RAP antagonists, downregulators, and blockers.

[0025] Furthermore, the reagent for inhibiting IL1RAP expression and / or function is a short hairpin RNA (shRNA) that specifically interferes with IL1RAP gene expression; the nucleotide sequence of the shRNA is selected from any one or more of SEQ ID NO.1-SEQ ID NO.5.

[0026] Furthermore, the reagent for inhibiting IL1RAP expression and / or function is a lentiviral vector containing shRNA that specifically interferes with IL1RAP gene expression.

[0027] Furthermore, the reagent used to inhibit IL1RAP expression and / or function is a pLKO.1 lentiviral vector containing the shRNA described above. To improve knockdown efficiency, cells can be co-infected with several knockdown sequences of lentivirus to construct stable knockdown cells.

[0028] A third aspect of the invention provides the use of an agent that inhibits IL1RAP expression and / or function in combination with a PD-1 monoclonal antibody in the preparation of a medicament for the prevention and / or treatment of liver metastases from breast cancer.

[0029] A fourth aspect of the present invention provides a pharmaceutical composition for the prevention and / or treatment of liver metastases of breast cancer, said pharmaceutical composition comprising an agent that inhibits IL1RAP expression and / or function, and a pharmaceutically acceptable carrier or excipient.

[0030] Furthermore, the pharmaceutical composition also includes a PD-1 monoclonal antibody.

[0031] The advantages of this invention are:

[0032] 1. This invention reveals for the first time the crucial promoting role of IL1RAP in liver metastasis of breast cancer, filling a gap in this technical field. Existing research only focuses on the function of the IL-1 receptor family in immune cells or the general proliferation and metastasis mechanisms of tumor cells. However, this invention, through in vivo screening of the entire IL-1 receptor family, is the first to systematically identify IL1RAP on tumor cells as the core molecule specifically regulating liver metastasis. Knockdown of IL1RAP can significantly inhibit the formation of liver metastases (inhibition rate of approximately 70%) without affecting the growth of in situ tumors, demonstrating good organ selectivity and potentially reducing systemic toxicity. At the mechanistic level, this invention elucidates for the first time the complete pathway of the IL1RAP / NF-κB / CCL4 / CCR5 signaling axis regulating the immune microenvironment of liver metastasis: tumor cell IL1RAP upregulates CCL4 secretion by activating NF-κB. CCL4 binds to the CCR5 receptor on macrophages, promoting the recruitment of tumor-associated macrophages and M2 polarization, forming an immunosuppressive microenvironment.

[0033] 2. This invention further utilizes single-cell sequencing technology to perform high-resolution analysis of immune cells in liver metastases, identifying for the first time three macrophage subsets that were significantly reduced after IL1RAP knockdown. These three subsets all highly express M2 macrophage-related genes (such as Arg1, Mrc1, Cd163, and Il10) and commonly express three characteristic molecules: MGP (Matrix Gla Protein), TMEM176A, and TMEM176B. In vitro co-culture experiments further confirmed that knockdown of tumor cell IL1RAP significantly inhibited the expression of MGP, TMEM176A, and M2 markers in co-cultured macrophages; simultaneously, macrophage migration ability was also significantly reduced. Multicolor immunofluorescence of mouse liver metastases revealed: MGP... + TMEM176A + Macrophage infiltration was also significantly reduced in the IL1RAP knockdown group. These findings not only reveal the molecular basis of IL1RAP regulation of specific tumor-promoting macrophage subsets in the liver metastasis immune microenvironment, but also provide a new potential intervention point for targeting MGP or TMEM176A / B positive macrophages.

[0034] 3. This invention provides a clear molecular node for targeted intervention. Knockdown of IL1RAP significantly inhibits the formation of liver metastases from breast cancer in mice, and its combined use with PD-1 monoclonal antibodies produces a significant synergistic anti-tumor effect, while also significantly reducing MGP in liver metastases. + TMEM176A + Macrophage infiltration effectively addresses the clinical challenge of poor response to immunotherapy in liver metastases. The target and combination therapy strategies provided by this invention cover multiple forms, including gene therapy and antibody drugs. Since IL1RAP specifically functions in liver metastases, targeting this molecule is expected to reduce side effects on normal tissues. It boasts significant advantages such as a short clinical translation cycle, clear safety profile, and great potential for expanding indications, possessing extremely high scientific value, clinical development prospects, and market potential. Attached Figure Description

[0035] Figure 1 The relationship between IL1RAP expression and prognosis in breast cancer patients. A: Overall survival (OS) curves for patients with high and low IL1RAP expression; B: Delayed survival (DMFS) curves for patients with high and low IL1RAP expression.

[0036] Figure 2 Knockdown of IL1RAP inhibits liver metastasis of breast cancer in mice. A: Fluorescence imaging of mouse liver; B: Gross photograph of liver and statistical count of metastatic nodules on liver surface in a liver metastasis model injected into the spleen; C: Growth curve of orthotopic xenograft tumor.

[0037] Figure 3IL1RAP knockdown remodels the immune microenvironment of liver metastases. A: Flow cytometry analysis of changes in the proportion of macrophages in liver metastases; B: Flow cytometry analysis of changes in the proportion of T cells; C: Multiplex immunofluorescence staining of changes in the proportion of macrophage infiltration.

[0038] Figure 4 Single-cell sequencing identified specific tumor-promoting macrophage subsets regulated by IL-1RAP. A: CD45 in liver metastases. + B: UMAP clustering diagram of immune cells. C: Volcano plot of differential gene analysis of three macrophage subsets between the control group and the IL1RAP knockdown group. D: GO enrichment analysis of macrophages in high-expression and low-expression groups based on MGP and TMEM176A / B expression levels. E: mRNA expression levels of MGP, TMEM176A, TMEM176B and M2 markers (Arg1, Mrc1) in iBMM macrophages after co-culturing with control or IL1RAP knockdown tumor cells in an in vitro co-culture system (qRT-PCR). F: MGP expression in liver metastases from IL1RAP knockdown and control mice. + TMEM176A + Macrophage staining. F: MGP in mammary tumor tissues from IL1RAP knockout and control mice. + TMEM176A + Macrophage staining.

[0039] Figure 5 IL1RAP regulates macrophages through the NF-κB / CCL4 axis. A: Transcriptome sequencing showed that CCL4 expression decreased after IL1RAP knockdown; B: NF-κB inhibitors blocked IL1RAP overexpression-induced CCL4 upregulation; C: CCL4 complementation experiments restored macrophage recruitment capacity.

[0040] Figure 6 Targeting IL1RAP enhances the anti-liver metastasis efficacy of PD-1 monoclonal antibodies. A: Gross liver photographs of the combination therapy group and statistics on the number of liver metastatic nodules in each group. B: Arg1 in each group. + MGP + TMEM176A + Macrophage staining and statistical analysis. Detailed Implementation

[0041] The specific implementation methods provided by the present invention will be described in detail below with reference to the embodiments.

[0042] Example 1: IL1RAP knockdown inhibits liver metastasis of breast cancer

[0043] (1) Cell line construction: Using the pLKO.1 lentiviral vector, a stable knockdown cell line (shIl1rap) targeting the mouse Il1rap gene and a control shSCR cell line were constructed. The knockdown efficiency was verified by qRT-PCR and Western blot.

[0044] Table 1. Nucleotide sequence of shRNA in Example 1

[0045]

[0046] (2) Liver metastasis model: Six-week-old female C57 mice were injected with 1×10⁻⁶ liver metastases via the spleen. 4 One tumor cell (shSCR or shIl1rap). Three weeks later, the mice were sacrificed, the livers were removed, and the metastatic nodules on the liver surface were counted, weighed, and photographed. Figure 2 A).

[0047] Results: Compared with the shSCR group, the number of metastatic nodules on the liver surface of mice in the shIl1rap group was reduced by approximately 70% (P<0.001), and the liver weight was significantly reduced (P<0.01). This indicates that knockdown of IL1RAP can significantly inhibit liver metastasis of breast cancer. Figure 2 B).

[0048] Example 2: IL1RAP regulates the immune microenvironment of liver metastasis

[0049] Liver metastatic tissue from Example 1 was used to prepare a single-cell suspension for flow cytometry analysis. The results showed that the proportion of F4 / 80+CD11b+ macrophages in the liver metastases of the shIl1rap group was approximately 50% lower than that of the shSCR group (P<0.01), while the proportion of CD8+ T cells was significantly higher (P<0.05). Figure 3 A, B). Multiplex immunofluorescence staining further confirmed the above results ( Figure 3 C).

[0050] Example 3: Single-cell sequencing verification of IL1RAP regulating MGP⁺TMEM176A⁺ macrophage subset

[0051] Liver metastasis tissue was harvested 21 days after spleen injection and single-cell sequencing was performed. Raw data were processed using Cell Ranger, and dimensionality reduction clustering and differential gene analysis were performed using Seurat software.

[0052] Results: CD45⁺ cells were extracted and clustered into 17 major immune cell populations ( Figure 4 A). Compared with the shSCR group, the proportions of the three macrophage subsets decreased in the shIl1rap group. All three subsets highly expressed M2 type markers and, in the control group, commonly expressed MGP, TMEM176A, and TMEM176B. Figure 4 B). Macrophages were divided into high and low expression groups based on the median expression values ​​of MGP and TMEM176A / B for GO analysis. The high expression group was significantly enriched in pathways such as "cell chemotaxis", "macrophage migration", "IL-1 secretion", and "IL-10 signaling pathway". Figure 4 C).

[0053] Table 2. Primer sequences used in Examples 3 and 4

[0054]

[0055] Example 4: IL1RAP regulates macrophages through the NF-κB / CCL4 axis

[0056] (1) Transcriptome sequencing: Total RNA was extracted from shSCR and shIl1rap cells and sequenced. CCL4 was found to be one of the most significantly different chemokines. Figure 5 A). qRT-PCR confirmed that CCL4 expression decreased after IL1RAP knockdown.

[0057] (2) NF-κB pathway validation: qPCR showed that NF-κB inhibitor treatment could inhibit IL1RAP overexpression-induced CCL4 upregulation ( Figure 5 B).

[0058] (3) Macrophage recruitment experiment: Transwell chambers were used, with tumor cells seeded in the lower layer and iBMM macrophages added to the upper layer. The results showed that the number of macrophages migrating in the shIl1rap group was reduced by about 60% compared with the shSCR group; exogenous supplementation of CCL4 could partially restore migration ability ( Figure 5 C).

[0059] Example 5: Targeted IL1RAP combined with PD-1 monoclonal antibody for the treatment of liver metastases

[0060] Mice were randomly divided into four groups: control group, PD-1 monoclonal antibody group, shIl1rap group, and shIl1rap + PD-1 monoclonal antibody group. After splenic injection of shSCR or shIl1rap cells, PD-1 monoclonal antibody (5 mg / kg) was administered intraperitoneally. Mice were sacrificed on day 21 to assess liver metastasis. Results showed that the shIl1rap + PD-1 monoclonal antibody group had the fewest liver metastatic nodules, approximately 85% fewer than the control group, demonstrating a significant synergistic effect. Figure 6 A). Multicolor fluorescent staining results showed that MGP + TMEM176A + Macrophage infiltration also decreased accordingly. Figure 6 B).

[0061] The above results indicate that IL1RAP is an effective therapeutic target for liver metastases in breast cancer. By inhibiting its expression or function, it can block the NF-κB / CCL4 / CCR5 signaling axis, reduce tumor-associated macrophage recruitment and M2 polarization, and reverse the immunosuppressive microenvironment, thereby inhibiting liver metastases.

[0062] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. Application of reagents that inhibit IL1RAP expression and / or function in the preparation of drugs for the prevention and / or treatment of liver metastases of breast cancer.

2. The application according to claim 1, characterized in that, The reagents that inhibit IL1RAP expression and / or function include, but are not limited to: Antibodies or antigen-binding fragments that specifically bind to IL1RAP; siRNA, shRNA, antisense oligonucleotides that specifically interfere with IL1RAP gene expression, or recombinant vectors or recombinant viruses containing the above interfering molecules; A CRISPR-Cas9 gene editing system targeting IL1RAP; IL1RAP antagonists, downregulators, and blockers.

3. The application according to claim 1, characterized in that, The reagent that inhibits IL1RAP expression and / or function is an shRNA that specifically interferes with IL1RAP gene expression; the nucleotide sequence of the shRNA is selected from any one or more of SEQ ID NO.1-SEQ ID NO.

5.

4. The application according to claim 3, characterized in that, The reagent used to inhibit IL1RAP expression and / or function is a lentiviral vector containing shRNA that specifically interferes with IL1RAP gene expression.

5. The application according to claim 4, characterized in that, The lentiviral vector is pLKO.1 lentiviral vector.

6. Application of reagents that inhibit IL1RAP expression and / or function in combination with PD-1 monoclonal antibodies in the preparation of drugs for the prevention and / or treatment of liver metastases of breast cancer.

7. A pharmaceutical composition for the prevention and / or treatment of liver metastases from breast cancer, characterized in that, The pharmaceutical composition comprises an agent that inhibits IL1RAP expression and / or function, as well as a pharmaceutically acceptable carrier or excipient.

8. The pharmaceutical composition according to claim 7, characterized in that, The pharmaceutical composition also includes a PD-1 monoclonal antibody.

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